Preparation of polyamides

US6429279B1 · kind B1 · utility

Assignee

• BASF SE

Inventors

• Hans-Harald Hünger · Ellerstadt, DE
• Alfons Ludwig · Ankum, DE
• Rainer Neuberg · Schifferstadt, DE
• Gunter Pipper · Bad Dürkheim, DE
• Thomas Sauer · Hochheim, DE
• Axel Wilms · Bad Dürkheim, DE

Key dates

• Filing date: May 11, 2000
• Grant date: Aug 6, 2002
• Expiry date: May 11, 2020

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G69/16
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The disclosure is a process for preparing polyamides by concentrating the wash water extract from the extraction of polyamide to an extractables content of not more than 85% by weight, adding fresh lactam down to a water content of from 0.5 to 13% by weight, and effecting at least one adiabatic expansion during the polymerization.